Downshift problem

[denngril]

Hi all. Wife took our 2001 in for a tranmission filter/fluid service to a reputable shop. Immediately after, she noticed the transmission seems to hang the 2 to 1 downshift. Shop says they used the proper +4 fluid. Upon a return to the shop, manager drove it and confirmed the problem. Scheduled an open-pan inspection next week. This car has about 70K of middle age driver miles on it..the shop stated the pan was immaculate. Any ideas as to the cause of this sudden problem?

Thanks!
Denny

[CREWZIN]

I did a fast search and there was one that I found that was near to your problem. One of the answers was from someone that seemed to know what he was talking about.

The trans module can store codes and they need to be read to see if any
exist and then go from there. Clutch volumes need to be carefully looked
at.
Did the battery get disconnected for any reason? This could have wiped
out the pinion factor and it needs to be put back into the t.c.m since this
tells the controller what size tire and rims are on the car and this can
mess with shifting.

[BLUEH20]

Pinion factor is stored in non-volitable (sp) memory on a eprom. Disconnecting the battery or the battery going dead or changing out the battery will not erase the pinion factor.

[denngril]

Hi Again!
Update on the shifting issue: Owner of the shop had the car for another day testing and exploring; took it out with his scanner connected for an afternoon, no codes or other maladies reported. He states that the problem may be an issue of the computer re-learning due to a pressure difference from the filter change, or perhaps a slightly different formulation in the fluid from his bulk supplier. He again pulled the pan for inspection, again finding it immaculate, and changed the fluid with another batch. In any case, he says he will stand behind whatever it happens, he has been very honest and up front with us, as he has been in the past. My curiosity is deeply troubled, as I am a mechanic, albeit not for transmissions, and the unknown causes me concern. I will post with more info when and if I have any.

Denny

[nodd89]

theres a tsb on it 18-007-01
i cant post it cause its a pic and it would void my agreements but tell ur mechanic to take a look at it...it fits close enough...and my car falls under another tsb for this same thing just in 2007

[CREWZIN]

I agree with nodd89. Here's something from another PT forum..........

There is a Technical Service Bulletin out, TSB 18-007-01, that I read about that may help with the automatic shifting problem you are bringing up. From a previous post:

"The bulletin effects Pt Cruisers with automatics built before 02-08-01. The fix is a software update to improve the feel of a 2-1 coast down bump and a better passing gear response from 3-1 or 2-1. The update is supposed to provide a smoother crisper shift and get rid of the coast down bump. The soft ware will make lock-up of the torque converter
less sensitive to throttle changes while on the highway. Recommend if you want the up date complain of a firm down shift when coasting to a stop sometimes."

[Gomanngo]

Sorry for the ignorance, but do I understand that this is something covered, a recall of sorts, if I take it to a Chrysler dealer?

[CREWZIN]

No, sorry, this is a TSB (Technical Service Bulletin) that Chrysler puts out telling the mechanics the best way to fix something, what's been discovered, how to save time in fixing a particular part. It could still be covered under whatever warranty you or any other owner has in effect but the Bulletin is just for informational purposes for the dealer.

[denngril]

First I must thank you all for the insight and information! We took the car into the dealer and explained what had transpired. They understood immediately, and flashed the DTM and re-programmed. The work order lists the cause as "DTC loss of prime, volume index out of range (air in system from service) "Performed quick learn and re-programmed"
Now I wonder..did the guy servicing the filter start it up before the trans was full?? In any case, I'm pleased that the wife's "baby" is healed, albeit the extra $90 charge does grate on me a bit, but less than a rebuild! I hope other owners don't have this occurance, and if so, I hope this info can help.

Again, Thank You!
Denny

[denngril]

Spoke with the transmission shop owner today, he asked to see the repair invoice from the dealership. he surmises this MAY have been caused by his equipment aereating the fluid from his bulk supply; in any case, he cheerfully worte out a check to cover the dealer's bill. And he did this unsolicited! So..we're back to "normal"!

Denny